1. Field of the Invention
The present invention relates to laser beam image forming apparatus, and particularly to laser beam image forming apparatus capable of automatically differentiating types of photosensitive sheets.
2. Description of the Related Art
Laser beam image forming apparatus in which a photosensitive sheet is exposed with a laser beam optical-modulated on the basis of image data for forming an image has been known. This kind of apparatus requires adjustment of intensity of the laser beam according to sensitivity of photosensitive sheets. Accordingly, conventional apparatus include one in which an operator sets sensitivity of a photosensitive sheet according to the sensitivity of the used photosensitive sheet using a sensitivity setting switch, and one in which a code label indicating sensitivity of photosensitive sheets provided on a magazine accommodating the photosensitive sheet is read out by a device in order to automatically set the sensitivity.
In the former one, however, there have been problems that the sensitivity setting by an operator is complicated and that mistakes are frequently made in setting the sensitivity. Also, the latter one requires standardization of code patterns indicating sensitivity and of positions at which code labels are provided on magazines, so that it has been difficult to satisfy various kinds of needs.